I have the 848 Superbike, I've had it about a year. In terms of general maintenance, it actually hasn't cost me all that much. But I haven't really ridden it much over the last year (I'm in and out of the country a lot), the bike just had its 12000KM service a couple weeks ago (Bike needs servicing every 12k KM IIRC). Cost me about 8XX all in, but I had a couple of extras included in that bill so maybe, 7XX? That included checking the valves etc as well. It's not expensive provided nothing needs to be replaced. Then it could've gotten nasty.

Most common parts are generally pretty easy to find. I wouldn't say I've had to wait 3 weeks for anything, but then nothing has really been wrong with my bike, except a small nagging immobilizer issue that comes up now and again (we're working on a fix for that).

Tyres, for a set of pirelli supercorsa SC2's for my bike for example would be about RM1450 fitted (that's the best I've seen so if anyone has any other places to go please do share). This is for a 180 section rear tyre. The 190's that are used on the 1098/1198 are a bit more at RM1500 I think last time I checked.

My advice for anyone with Ducati buying intentions is make sure you follow the service manual and service interval schedule, even if the bike is running well. Otherwise things break, then your wallet will cry